Electrical recorder reproducer



p 193W H. W. ROGERS ELECTRICAL RECORDER REPRODUCER Original Filed March 10.

Patented Sept. 16, 1930 UNITED STATES PATENT OFFICE Application filed larch 10, 1927, Serial ll'o. 174,188. amivea larch 4, 1980.

This invention relates to improvements in electrical recorder-reproducers and more particularly to that type of magnetic recorder-reproducer used in conjunction with the power amplifying circuits in making and reproducing sound records, one object of the invention being the provision of device of this. character which is sim le durable and practical in construction an thoroughly efficient in use.

A further object of this invention is the provision of an electric recorder-reproducer of the magnetic type in which the armature is so mounted as to oscillate or be oscillated by a stylus carrying member, which is normally held biased to a neutral position, thus preventing any undue vibrations or oscillations either set up at the initial movement from the sound groove while reproducing or from the magnetic effect when used as a recorder.

Still further object is the rovision of an electric recorder-producer o the magnetic pick-up type, in which the whole device is nicel balanced in a frame or arm that is itsel mounted to swing over the record as well as to and from the same so that the least possible weight is exerted downwardl through the stylus upon the record, yet su ficiently pressed down as to form the record groove inthe master record when recording and ride in the sound groove when reproduc- TVith the foregoing and other objects in view, the invention resides in the arrangement and combination of parts as hereafter set forth and more particularly claimed, reference being had to the accompanying drawin s, in wh1ch:

igure 1 is a side elevation of the complete pick-up.

.Figure 2 is a top plan view thereof.

Figure 3 is a section or line 3-3 of Figure 2.

Figure 6 is an enlarged detail view of the Figure 4 is a perspective view of the armaouter end of the stylus carrying rod and its sprin support.

- Re erring to the drawings, the numeral 10 designates the base of the support 11, which is swivelled or pivoted for horizontal swingas ing movement, which adjustably supported by the adjusting pintles or screws 12 to the support 11, is the frame or arm 13 of the device.

This frameor arm is open throughout its to central portion to provide the rear closed end 14, and the tapered forward end 15. Fitted within the end 14 and also acting as a counterbalance for the long free end of the frame, is the bi-polar permanent magnet 16, whose respective north terminal 17 and south terminal 18, project toward the pivotal point of the frame, there being attached to the terminal 17 the two (pole pieces 19 and 20, projccting toward an spaced from the two pole 10 pieces 19 and 20 carried by the terminal 18 of the magnet. A steel rod 21, preferably a drill rod is mounted centrally and longitudinally of the frame, and is supported at its rear end b a flat torsion spring 24, in 7 turn supports by the plate 25, while its forward end is supported by the flat torsion spring 22, through the medium of the ad- 'usting device composed of the screw 23 and 1ts nut 23. By this means the rod 21 is held so in a neutral or central position, but permitted a limited oscillatory movement relative to its longitudinal axis, the purpose of which will presently appear.

The armature 26 is fast upon the rod 21 86 and is com osed of a series of laminations 27 of .150 sllicon steel plates, formed in contour to fit within the space between the inner ends of the respective pole pieces 19-19 and 20-20, with a limited movement therebetween. Two coils 28 and 28, are carried by the armature, and these coils are connected to the terminals 30 and 31, for insertion in a circuit either for recording or reproducing. as

Carried by the rod 21 at its forward end and depending therefrom is the stylus carr ing arm 32, havin the lock screw 33 to hold the stylus 34 in p ace.

From the foregoing description, the operap tion and use of the resent invention is readily understood, but riefiy stated it is as follows. a

As a recording device thecoils 28-28 are connected in/an amplifying circuit under the influence of the microphone or other electrical transmittin device, and as the flow of current to' and t rough the coils is influenced, the efi'ect of magnet is to cause the armature to. oscillate, thus movin the stylus to, provide or form sound in entations upon the wax record, which is revolved in theusual manner, the two torsion springs 22 and 24, permitting this action but also preventing any undue movement in therod,so' that no false movements are imparted to the stylus. As a reproducing device or ick-up, the coils are connected in an ampli yin circuit, which in turn is provided with a lou speaker and its various means ,for staging various stages of amplification. The stylus is then placed in the sound groove of a soundrecord which in turn is revolved, this action causing the lateral indentations or sound reproducing parts in the groove to impart lateral oscillatory movements to the rod 21 and the armature, which in turn influences the pole pieces of the magnet and thus transmits variations inthe current flow in the circuit so that the sound is reproduced in the loud speaker. The

torsion springs in this instance tend toand do prevent any too sudden or great movement in the rod 21, and thus the soundis'reproend, a s ring supported oscillatory armature mounte for lim1ted movement in the frame,

to be influenced by the poles of the magnet,

coils carried by the armature, a stylus carr ing member connected to move simultaneously with the armature, and a torsion s ring connected to the stylus car ing mem er to normally hold the said mom or and the armature in a neutral position.

4. An electric recorder-reproducer, including a swinging support, a magnet carried by the support, an oscillatory armature disposed to be influenced by the poles ofthe magnet, coils carried by the armature, astyIuscarryingmember connected to may s multaneous sion s rings 'ly with the armature, and two mem er to connected to the stylus ca normally hold the stylus c a and armature in a neutralfosition.

In testimony whereofI-a my signature.

HARRISON W. ROGERS.

duced as it should be from the very initial starting of the record.

The two springs ashereto stated act to hold the rod in a neutral or'unbiased position, the

magnet acts as a counterbalance 1n the frame or arm, and by means of the nut and screw adjustment the tension of the spring sup ort maylbe varied as required to produce the est resu ts.

It is evident that with a recorder-reprodue er constructed as here set forth, that a very simple device of this type is provided, one

that is not likely to get out of order, and which will record or reproduce in a most eflicient manner-without extraneous sounds due to mechanical oscillations of the stylus carrying member at the initial startin of the operations'of recording and repro ucing.

What I claim as new is z 1. An electric recorder-reproducer, including a swinging support, a magnet carried thereby, a rod, a stylus carried thereby, spring supports for the rod and for connecting the rod to the frame and permitting the rod limited oscillatory movement, and-an armature provided with coils carried by the rod, said armature being disposed between the poles of the magnet.

ing member.

2. An electric recorder-reproducer, includ ing a frame pivotally and swinginglymounted, a magnet mounted in the frame at one end and acting as a counterbalance for the other 

